1. Field of the Invention
Apparatuses consistent with the present invention relate to a concurrent mode antenna system, and more particularly, to a concurrent mode antenna system for enabling various radio communication services by transmitting and receiving radio signals of a plurality of frequency bands on a single antenna.
2. Description of the Related Art
Various radio communication services use wireless terminals such as mobile phones, personal digital assistants (PDAs), persona computers, and notebook computers, for example, Global System for Mobile communication (GSM), Personal Communication Services (PCS), World Interoperability for Microwave Access (WiMAX), Wireless Local Area Network (WLAN), Wireless Broadband Internet (WiBro), and Bluetooth.
GSM uses a 890˜960 MHz band, the PCS uses a 1.8 GHz band, and WiMAX uses a 3.6˜3.8 GHz band. WLAN uses a 2.4 GHz band which is the Industrial, Scientific & Medical (ISM) band in the IEEE 802.11b standard and a 5 GHz band which is the Unlicensed National Information Infrastructure (UNII) in the IEEE 802.11a standard. WiBro uses a 2.3 GHz band and Bluetooth uses a 2.4 GHz.
To use radio communication services at a single wireless terminal over the various frequency bands, the related art employs a multiband antenna system as shown in FIGS. 1 and 2.
The multiband antenna system in FIG. 1 includes a single antenna 10, a multiplexer 15 for separating signals from the antenna 10 into a plurality of frequency bands, f0˜fn, and a plurality of radio frequency (RF) circuits 20 for processing the frequency band signals separated at the multiplexer 15.
The antenna system of FIG. 1, which uses the single antenna 10, can decrease the size of the antenna system but may be subject to the insertion loss due to the multiplexer 15. With the single antenna 10, only one radio communication service can be used at a time, because it is impossible to provide the corresponding radio communication services with respective frequency bands at the same time.
The multiband antenna system in FIG. 2 includes a plurality of antennas 50, a plurality of band pass filters (BPFs) 55, and a plurality of RF circuits 60. The antennas 50 transmit and receive signals in different frequency bands, f0-fn. The BPFs 55 filter the signals transmitted and received on the antenna 50 according to the intended frequency bands.
Using the multiple antennas 50 and the multiple BPFs 55, disadvantageously, the antenna system of FIG. 2 generates the insertion loss and increases the size of the antenna system.
Therefore, what is needed is a reconfigurable antenna system which can receive various radio communication services on a single antenna, use the radio communication services at the same time, and reduce the insertion loss of the conventional multiband antenna system that are due to the multiplexer 15 or the BPF 55.